1. Field of the Invention
The invention relates to a circumferential seal with a static portion and a rotating portion and more specifically to the arrangement of the static portion.
2. Description of Related Prior Art
Circumferential seals can be used in operating environments in which one component is rotating and a second component is stationary. The circumferential seal can prevent leakage of fluid along the axis of rotation, especially where the rotating component passes through a wall or partition. The rotating component is usually called a seal runner and the non-rotating or static component can be referred to as a seal assembly or seal stator. A sealing element is usually contained within the static seal housing and contacts the seal runner to form the primary sealing interface. The seal runner can be made of metal or other materials and can be mounted to a rotating structure, such as a shaft. The seal runner can have a surface facing radially outward for sealing. The seal element can include a sealing surface that faces radially-inward. The two surfaces cooperate to seal a leakage path between rotating components and static components. A small radial gap can be maintained between the sealing element and the seal runner under some operating conditions to allow for an insignificant amount of leakage across the seal and prevent damage to the seal element. Circumferential seal arrangements can be “buffered” in that a flow of pressurized fluid can be directed into the seal housing to positively separate the fluids on opposite axial sides of the seal element. The fluid entering the seal housing is at a higher pressure than the fluids on opposite axial sides of the seal element.